The present invention relates to space heating apparatus and more particularly to an improved fuel burner assembly which provides a stable, non-pulsating flame wall proximate the outlet of a burner duct.
Various burner devices have been employed in the past which include a burner duct into which fuel and air are injected and burned and from which the heated combustion products are introduced into a heated combustion chamber and subsequently to a heat exchanger. A number of arrangements have been employed to divert the air in a preselected pattern to be mixed with a fuel for burning, attention being directed to several such arrangements as disclosed in the long since expired U.S. Pat. No. 1,512,132, issued to F. G. Pfahl on Oct. 21, 1924, and the more recently expired or soon to expire U.S. Pat. No. 3,109,481, issued to R. L. Yahnke on Nov. 5, 1963; U.S. Pat. No. 3,223,136, issued to P. A. Mutchler on Dec. 14, 1965; and U.S. Pat. No. 3,593,969, issued to H. R. Smithson et al on July 20, 1971. These abovementioned patents all have been concerned to various extents in establishing efficient stable flame production, but none has recognized or resolved those problems which have been recognized and solved by the unique and novel fuel burner apparatus described herein.
In accordance with the present invention, a novel burner assembly is provided which recognizes that forced draft heating systems, as distinguished from natural draft or balanced draft heating systems, require burner pressures sufficient to overcome the resistances offered by the combustors and heat exchangers with which they are coupled, particularly those combustor-heat exchanger arrangements wherein the flame delivered by the burner follows a first direction and is then reversed in direction to the flue gas outlet. In addition, the present invention recognizes the desirability of a burner arrangement which can establish a stable non-pulsating flame wall or front--that is the location of a plane normal to the longitudinal axis of a burner where the flame steadily burns. The present invention further recognizes that it is desirable that such a flame wall be not only stable but continuous over a broad range of temperatures and that it be operative in various environmental or ambient extremes to which a selected burner and associated equipment might be subject.
Recognizing these burner problems, the present invention provides a burner assembly which can be economically and efficiently manufactured and assembled with a minimum of parts and a minimum of maintenance, the inventive burner assembly producing a comparatively quiet, non-pulsating flame. Further, the fuel burner assembly of the present invention is capable of starting and operating for long periods of time over comparatively wide ranges of firing rates and varying ambient conditions with relatively high thermal efficiency and low contaminant production.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosures set forth herein.